Hi
Recently my company purchased Blackberry 8820 .
One of our system guys tried t install OS version 4.5 on it.
This attempt failed and now device is unusable.
When switched on it shows some text menu titled Blackberry Platform 2.7.0.55 , but you cant push on menu items it leads to message box with error description.
When i connect it to my comp , it shows up as remote storage device ,but Desktop manager does not recognize it.
How can i install previous version of OS on such device?
Is there any way to do hard reset to bring device back to some state were you can actually do something with it?
Thanks.

Ive tried to follow instructions from the link you gave me.
When i run Loader.exe it asks me to select Communication port to which my device connected.Combo box has 2 values COM1 and USB-PIN:241f9864 ,if i press next value in combo box changes to be COM1 and then USB:UNKNOWN , after that i see page with error message that says that BlackBerry desktop software does not have Device software for device im using.
Any ideas?

I have the os installed on my PC.
Ive reisntalled it like 5 times with restarts of PC registry clean ups in between and everything possible to assure proper software instalation.
Still same result.
Instalation program shows USBL:PIN in combo box, after i push Next button, it changes to COM1 and then shows error message that it unable to connect to device.
Ive tried to install previous OS version 4.2.2 , same result.
Any ideas?